The Sex Discrimination Commissioner says no sector is immune from discrimination.

AAP: Tracey Nearmy

Almost 50 per cent of mothers have experienced discrimination in the workplace at some point during pregnancy, parental leave or when they returned to work, a new study shows.

The landmark study by the Human Rights Commission found that the consequences are keenly felt, with 84 per cent of women reporting mental and physical stress, and damage to their finances and career.

The report found 49 per cent of pregnant women and working mothers experienced discrimination both in the corporate world and the public service.

The commission surveyed hundreds of parents, employers and business groups and found cases where maternity leave was denied, job contracts were torn up, careers were stunted, while demotions and resignations were commonplace.

One woman was advised by her boss to consider an abortion, while another was told to chose between her baby and her job.

Sex Discrimination Commissioner Elizabeth Broderick says no sector is immune from this discrimination.

"I spoke to women who had roles on a factory floor, through to the most senior executives, the most senior medical specialists in this country, and it was pervasive across all levels and all sectors," Ms Broderick said.

"I think what disturbed me most was almost the inevitability of it. It was almost as if well, 'I just have to put up with this because this is part of the landscape'.

"I think probably the worst for me was a woman that I met who was working in a male-dominated industry when she said to her manager that she was pregnant. The immediate response was 'well, your choice, the job or the baby'.

"For that woman and her partner, they decided they desperately needed the job.

"She had a termination and then she lost her job several weeks later."

Men also face discrimination after parental leave

Ms Broderick says men face discrimination as well.

"Twenty-seven per cent of men who'd taken a month or less had experienced discrimination on return from parental leave," she said.

"I mean that's less than their annual leave entitlement so I have to say that was a very surprising figure."

The report also found when it came to discrimination, it did not make a difference whether the boss was female or male.

"One of the other disturbing things for me was that many of the discriminatory views came from other women, female managers, often managers who had children themselves and I have to say as Australia's Sex Discrimination Commissioner, I found that deeply depressing," Ms Broderick said.

Apart from the deep personal and professional losses, discrimination has broader economic costs, Ms Broderick says.

"For an individual woman or man affected by it, it's about the mental health impacts, it's about loss of job security, it's about financial impacts. It impacts on the family," she said.

"I met people who because of one partner, the pregnant woman being pushed out of work, could no longer afford their mortgage."